This invention relates to an emergency exit system and in particular to an emergency exit system for use on a helicopter or other aircraft.
Vehicle accidents occurring in water have a lower survival rate than accidents occurring on land. In water accidents, the vehicles usually sink very rapidly, either in an upright or inverted position. Underwater conditions are drastically different from land based conditions. Visibility is reducedxe2x80x94the majority of people can see only 1.5 meters underwater and 3.1 meters in the best lit conditions. Survivors of a crash or forced landing must depend on their breath-holding ability to make a successful escape. Generally, a person""s breath-holding ability is reduced 25-50% in water under 15xc2x0 C. Maximum breath-holding time can be as short as 10 seconds. Survivors are often disoriented due to the sudden immersion in water, loss of gravitational references, poor depth perception, nasal inhalation of water and darkness. Disorientation is magnified when the vehicle is inverted. Under the latter condition, finding a handle to jettison an escape door or window, which is a simple procedure to execute in an upright position on dry land, can be a most challenging task even if the handle is only a few centimeters away from the survivor""s hand.
Usually handles for open escape doors or windows are small, and are positioned between knee and chest level. The various positions would not be obvious to the survivor unless he or she is familiar with the particular escape system Most existing mechanisms are adapted to remove an entire door or window, including the frame, requiring a complicated jettison mechanism, which is not always dependable. Moreover, existing systems do not provide feedback to indicate that the door, window or hatch as been successfully jettisoned.
GB-A-761 627 and U.S. Pat. No. 3,851,845 disclose systems for the jettisoning of aircraft canopies or doors which are inappropriate for use in a door or window release. The U.S. reference teaches the use of lever or a lever and a handle combination for releasing a door. When submerged in water such a system could be difficult to operate, particularly when it is necessary to operate a handle and a separate lever to effect release of the door.
The object of the present invention is to provide an emergency exit system of the type which includes a plurality of actuators adapted""to operate independently of one another to effect release of a window or door panel to provide an escape exit.
Accordingly, the present invention relates to an emergency exit system including a frame for mounting in a vehicle, said frame having an opening for closing by a panel, a plurality of spaced apart latch means for releasably latching said panel in the frame; release means for simultaneously releasing all of said latch means; and principal actuation means located at a plurality of locations around the periphery of said frame for actuating said release means when any of said actuation means is actuated, characterised by cable means forming part of said release means and extending around a substantial portion of said frame to interconnect the release means associated with each said latch means.